Phishing email used in serious RSA attack surfaces

13 words upend the world's security

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The theft of secret data related to RSA's SecurID tokens used by 40 million employees to access sensitive networks likely started with a 13-word email, evidence uncovered through a researcher's dogged sleuthing suggests.

“I forward this file to you for review,” the unsigned email, sent to four employees of RSA's parent company EMC, stated. “Please open and view it.”

The never-before-seen email was uncovered by Timo Hirvonen, a researcher with antivirus provider F-Secure, a little more than five months after someone pierced RSA's defenses and stole undisclosed information related to SecurID. The attack has generated enormous interest among forensics and malware experts because it aided in the subsequent hack of defense contractor Lockheed Martin and possibly other RSA customers guarding mounds of classified data.

RSA had previously said the perpetrators sent two different phishing emails to a small group of lower-level employees over a two-day period. The messages were “crafted well enough to trick one of the employees to retrieve it from their Junk mail folder, and open the attached excel file,” RSA said. The company said the booby-trapped payload was a spreadsheet called "2011 Recruitment plan.xls" that contained a malicious Adobe Flash object, but it refused to share the binary with researchers outside the investigation.

Hirvonen was among the hordes of researchers who searched high and low for the malicious Excel file. He eventually wrote an application that analyzed malware samples for Flash objects. The tool uncovered an Outlook message file that turned out to be an email sent to the four EMC employees on March 3. Lo and behold, it contained the recruitment spreadsheet, including the malicious Flash object.

With the binary in hand, the researcher soon discovered someone had uploaded it to Virustotal on March 19, more than two weeks after the attack and a day after RSA publicly disclosed the attack. That meant the highly sought-after file was in front of researchers' noses for five months.

When the file is opened, it installs the Poison Ivy backdoor on the end-user's machine. As the Youtube video below demonstrates, there are no obvious signs anything nefarious is taking place.

The only thing that was advanced about the attack, F-Secure has concluded, was the exploit targeting the then-unknown Flash vulnerability. (Adobe has since patched it.) The rest relied on a few of the most basic social engineering ploys to trick an employee at one of the world's most trusted security company's into clicking on it.